Murphy will now look to his final event at the championships, the 50m Freestyle heats on Friday. There are no Irish swimmers in action at World Championships today.

The poolTomorrow, Sycerika McMahon will be back in the pool in the 100 metres freestyle and Fiona Doyle will race in the 200 metres breaststroke.

However yesterday American teenager Katie Ledecky smashed the world record in the women’s 1,500 metres freestyle final by more than six seconds during a glittering session for the United States

The 16-year-old from Bethesda, who also won the 400 freestyle gold medal on Sunday, powered away from defending champion Lotte Friis of Denmark in the final stages to break the previous best of 15:42.54 set by compatriot Kate Ziegler in 2007.

It was the second world record of the championships in the specially constructed pool at the hilltop Palau Sant Jordi after Ruta Meilutyte’s mark in qualifying for the 100 metres breaststroke on Monday.

Lithuanian Meilutyte went on to claim a first world championship gold for the tiny Baltic nation when she triumphed in yesterday’s final. She was unable to better Monday’s effort but still produced the second-fastest time ever of 1:04.42, just seven hundredths slower than her record 1:04.35.

Ledecky’s team mate Missy Franklin, who won four gold medals and one bronze in last year’s London Olympics, secured her second gold of the week with victory in the 100 metres breaststroke and Matt Grevers claimed the 100 metres backstroke title.